Bird Technologies 8920 Series - Manual (Page 23)

13
Coolant Level
Coolant lifetime will vary greatly depending on operating conditions. For heavy use (full RF power for long times,
high ambient temperature), check the coolant every 500 hours. If the load has only had light duty (fraction of full
power, low ambient temperature), then coolant inspection may only be necessary every 2,000 hours.
Note: Correct any coolant leakage before inspection. (See "Troubleshooting" on page 11)
1. Remove the load resistor (Refer to “Load Resistor” on page 18).
2. Ensure the coolant should be clear, with a faint yellow tinge, and have a slightly
sweet smell.
3. Do the following ff the coolant is black with a burnt or acrid smell:
a. Drain it
b. Add about 6.7 gal (25.2 L) of coolant.
Note: With the load still on end, the coolant level should be 4 3 ⁄
4
" (125 mm) below
the top surface of the resistor assembly mounting ring, at ambient temperature.
4. Add coolant if necessary.
Repair
RF Connector
The Model 8921, only, has a special Bird “QC” connector which allows easy changing of the RF connector. This does not
disturb the coolant seal or affect the electrical continuity of the load. To change the connector, proceed as follows:
1. Remove the four screws at the corners of the RF connector.
2. Pull the connector straight out.
3. Push the new connector in.
4. Ensure that the center pin on the connector is properly seated in the mating socket
on the load.
5. Replace the screws.
Note: If not using the connector normally supplied, frequency and power must
be limited to the capabilities of the connector.
WARNING
Disconnect the unit from all power sources before servicing. The unit may be energized from multiple sources.
The potential for electric shock exists.
WARNING
Oil is slippery. If a leak occurs, be careful not to fall.
CAUTION
Use only Bird coolant, P/N 5-1070, to prevent damage to the load.
WARNING
Disconnect the unit from all power sources before servicing. The unit may be energized from multiple sources.
The potential for electric shock exists.
WARNING
The vent plug must be used at all times when the unit is operating or cooling. Failure to do so could result in an
explosion or severe burns.